This invention relates to the solvent extraction of oleaginous seed materials, and more particularly to a novel process for treating oleaginous seed materials utilizing aqueous alcohol to produce a protein-containing flour.
In such copending application U.S. Ser. No. 611,066 there is disclosed a process for preparing a product high in protein wherein particulate oleaginous seed material is sequentially extracted in three steps, comprising: contact with a relatively dilute aqueous alcohol to remove carbohydrates and non-oil lipids; contact with concentrated alcohol to remove the dilute alcohol; and contact with concentrated alcohol at or near the boiling point to remove oil, followed by desolventizing of the residual solids matter. In a particularly preferred embodiment of such invention, the oleaginous seed material is sequentially extracted in four steps, comprising: contact with a relatively dilute aqueous alcohol to remove carbohydrates and non-oil lipids; contact with concentrated alcohol to remove water; contact with undistilled, recycled concentrated alcohol at or near the boiling point to partially remove oil; and contact with distilled concentrated alcohol at or near the boiling point to complete oil removal. A novel high protein product is obtained by desolventizing the extracted residue.
In said copending application, the specification was addressed to the production, particularly for human consumption of soy protein concentrate, a product which, by commercial definition, contains at least 70% protein. It is now apparent that soy flour, a product of unspecified, but lower protein content, will be an important commercial product, provided that it has certain desired characteristics. These characteristics are: that the product be free of the non-oil lipids that give soybean products a beany flavor, that the product be free of those carbohydrates that cause flatulence, and that the product be as white as possible. This continuation-in-part discloses a process essentially similar to that already disclosed in said copending application and additionally discloses a new process for producing such novel protein flour.